Stabilization of organic material with 2, 2&#39;-methylenebis



nite This application is a continuation of application Serial No.211,846, filed July 23, 1962, now abandoned, which in turn is a divisionof application Serial No. 45,784, filed July 28,1960, now US. Patent3,146,273.

This invention relates to novel phenolic compounds containing a halogensubstituent on the benzene ring, and more particularly to the use asantioxidants of methylenebis phenols which are halogen substituted.

It is an object of this invention to provide novel phenolic compoundshaving an extremely high degree of antioxidant and stabilizing activityin a wide variety of organic compositions. Another object of thisinvention is the provision of phenolic compounds which are outstandingantioxidants in organic media such as fuels, lubricant and polymericmaterial. A still further object is the provision of stabilized organicmaterial containing a novel phenolic compound. Another object is toprovide novel methods for the preparation of phenolic compounds. Otherobjects will become apparent by the following specification.

The objects of this invention are in part accomplished by a compoundhaving the formula:

where X is a halogen selected from the class consisting of chlorine,bromine and iodine.

The most particularly preferred compound of this invention is2,2-methylenebis(4-chloro-6-tert-butylphenol) which is both readilyprepared and, as will be further illustrated below, is an outstandingantioxidant additive.

The compounds of this invention find important utility as antioxidantsin a wide variety of oxygen sensitive materials. Thus, an embodiment ofthis invention is organic material normally tending to undergo oxidativedeterioration in the presence of air, oxygen, or ozone, protectedagainst such deterioration by the inclusion therein of a smallantioxidant quantity, up to about 5 percent, of a2,2-methylenebis-(4-halo-@tert-butylphenol) as defined above. As notedabove, a particularly preferred embodiment of this invention is organicmaterial containing the compound 2,2'-methylenebis-(4-chloro-6-tert-butylphenol) Thus, liquid and solid products derived from petroleumcrude are found to possess greatly increased storage stability by theuse of an antioxidant of this invention. For example, gasoline jet fuel,kerosene, fuel oil, turbine oils, insulating oils, motor oils andvarious waxes have increased oxidative stability when they contain anantioxidant of this invention. Likewise, liquid hydrocarbon fuels whichcontain organometallic additives such as tetraethyllead and otherorganometallic compositions which are used as fuel additives attainappreciably increased oxidative stability by the practice of thisinvention. Furthermore, such fuels which contain halogen rates Patent 03,290,259 Patented Dec. 6, 1966 and phosphorus-containing scavengers forthese organometallic compound are benefited by the practice of thisinvention. In addition to increased storage stability, lubricating oilsand functional fluids, such as automatic transmission and hydraulicfluids, both those derived from naturally occurring hydrocarbons andthose synthetically prepared, achieve a high degree of resistance tooxidation during use at elevated temperatures by the practice of thisinvention. It has been found that lubricating oils may be employed atextremely high temperatures without undergoing oxidative degradationwhen protected by an antioxidant of this invention. The addition ofsmall quantities of'the compositions of this invention to such materialsas hydraulic, transformer and other highly refined industrial oils, aswell as crankcase lubricating oils and lubricating greases prepared fromthese oils by the addition of metallic soaps, greatly increase theirresistance to deterioration in the presence of air, oxygen or ozone.Furthermore, the organic soaps used in the preparation of lubricatinggrease are themselves stabilized by the practice of this invention.

Organometallic compositions such as tetraethyllead and tetraethylleadantiknock fluids containing halohydrocarbon scavengers, dyes and whichmay contain various phosphorus compounds and other organometallicadditives are stabilized against deterioration during storage by theaddition thereto of an antioxidant quantity of the compositions of thisinvention.

The compositions of this invention are also extremely effectiveantioxidants for elastotmers including high mole cular weightunsaturated hydrocarbon polymers including both those derived fromnaturally occurring sources and those synthetically prepared. Thus,natural rubbers and synthetic rubbers, including oil extended rubbersand sulfur vulcanized rubbers are greatly benefited by the practice ofthis invention. Examples of the synthetic rubbers protected by thepractice of this invention include such synthetics as polybutadiene,methyl rubber, polybutadiene rubber, butyl rubber, SB-R rubber, GR- Nrubber, piperylene rubber and dimethylbutadiene rubber.

The practice of this invention is also useful in protecting parafiin andmicro-crystalline petroleum waxes against the oxidative deteriorationwhich leads to rancidity. Furthermore, the compositions of thisinvention are extremely useful in the stabilization of fats and oils ofanimal or vegetable origin which become rancid during periods of storagedue to oxidative deterioration. Typical animal fats benefited by thepractice of this invention include butter fat, lard, beef tallow, fishoilssuch as cod liver oil-as well as. various foods containing orprepared in animal fats which tend to deteriorate. These include, forexample, potato chips, fried fish, donuts, crackers, and various. typesof pastry such as cakes and cookies. Furthermore, fat fortified animalfeeds and fish meals used as animal feeds are greatly benefited by thepractice of this invention. Not only are these compositions protectedagainst oxidative deterioration but the inclusion of a composition ofthis invention in such materials inhibits the degradation of vitamins A,D and E and certain of the B complex vitamins. Examples of compositionscontaining oils derived from vegetable sources which are benefited bythe practice of this invention include castor oil, soy bean oil,rapeseed oil, coconut oil, olive oil, palm oil, corn oil, sesame oil,peanut oil, babassu oil, citrus oils, cotton seed oil and variouscompositions containing these, including peanut butter, peanuts andother whole nuts, salad dressings, margarine and other vegetableshortenings.

The compositions of this invention are also outstanding antioxidants forvarious organic compounds and polymeric materials including polystyrene,polyvinylchloride,

polyvinyl acetate, various epoxide resin-s, polyester resins andpolymers, including alkyds, and polymers of monoolefins, such aspolyethylene .and polypropylene.

A preferred embodiment of this invention is rubber (including naturalrubber, sulfur vulcanized rubber and synthetic rubber) normallysusceptible to oxidative deterioration inhibited against suchdeterioration by a small antioxidant quantity, up to about percent of a2,2-methylenebis-(4-halo 6 alkylphenol) compound as defined above.

Although concentrations of the 2,2'-methylenebis-(4 halo-6 alkylpherrol)compounds of this invention, up to 5 percent, may be employed, thecompounds are such effective stabilizers that concentration ranges offrom 0.001 to about 2 percent by weight are usually suflicient toeffectively stabilize the material to be protected (based on the weightof the material). The most preferred concentration range is from about0.2 to about 1.5 percent by weight of the additive based on the weightof material to be protected. Deviations from these concentrations areacceptable and sometimes useful depending upon the initial degree ofinstability of the material being stabilized and the severity ofconditions to which the finished product is to be subjected. Smalleramounts of the compounds may be employed when the material is to be usedat lower temperature and oxidation in storage is the primary problem.

The synthetic lubricants which are enhanced by the practice of thisinvention are, in general, non-hydrocarbon onganic compositions; iLe.,organic compositions which contain elements other than carbon andhydrogen. Examples of general classes of material which are protectedagainst oxidative deterioration by the inclusion therein of a2,2'-methylenebis-(4-halo-6-tert butylphenol) of this invention includediester lubricants, silicones, halogen containing organic compoundsincluding the fluorocarbons; p-olyalkylene glycol lubricants, andorganic phosphates which are suitable as hydraulic fluids andlubricants. Excellent results are obtained when a 2,2-methylenebis-(4-halo-6-tert-butylphenol) is added to any member of theseclasses of materials; however, it has been found that exceptionaloxidative stability is imparted to diester lubricants by the practice ofthis invention. Thus a synthetic diester lubricant containing from about0.001 to about 2 percent by weight of 2,2'-methylenebis-(4-halo-6-tert-butylphenol) constitutes a preferred embodiment of thisinvention. The synthetic diester oils stabilized by the practice of thisinvention include sebacates, adipates, etc., which find particular useas aircraft instrument oils, hydraulic and damping fluids, and precisionbearing lubricants. These diester oils are exceedingly difficult tostabilize under high temperature conditions. In this invention, use canbe made of a wide variety of diester oils of the type described in Industrial and Engineering Chemistry, 39, 484-91 (1947). Thus, use can bemade of the diesters formed by the esterification of straight chaindibasic acids containing from 4 to about 16 carbon atoms with saturatedaliphatic monohydric alcohols containing from 1 to about 10 carbonatoms. Of these diester oils, it is preferable that the alcohol used intheir preparation be a branched chain alcohol because the resultantdiesters have very valuable lubricating properties and the inhibitor ofthis invention very effectively stabilizes these materials againstoxidative deterioration. Thus, use can be made of oxalates, malonates,suocinates, glutarates, adipates, pimelates, suberates, azelates,sebacates, etc.

The diester lubricants used in the lubricant compositions of thisinvention have the formula:

/COOR1 where R is an aliphatic hydrocarbon radical which may besaturated or unsaturated and has from 2 to 14 carbon atoms and R and Rare straight or branched chain alkyl groups. The diesters utilized inthe preferred lubricant compositions include esters of succinic,glutaric, adipic, pimelic, suberic, azelaic and sebacic acid. Typicalexamples of such esters are diisooctyl azelate, di-(2-ethylhexyl)sebacate, di-sec-amyl sebacate, diiso octyl adipate, di-(Q-ethylhexyl)adipate, di-(Z-ethylhexyl) azelate, di-(l rnethyl-4-et-hyloctyl)glutarate, diisoamyl adipate, di-(Z-ethylhexyl) glutarate, -di4(2ethylbutyl) Iadipate, ditetradecyl sebacate and di (2- ethy'lhexyl)pinate.

The preferred diesters are generally prepared by esterifyin'g one moleof a 'dicarboxylic acid having the general formula: HOOO(CH COOH, wherex is an in teger of from 2 to 8, with 2 moles of a branched chainalcohol containing at least 4 carbon atoms. Typical are the reactions ofsuccinic, gl-utaric, adipic, pimelic, suberic or .azelaic acid withsec-amyl alcohol, 3-ethyl butanol, Z-ethyl hexanol or the branched chainsecondary alcohols undecanol or tetradecanol.

The preferred diester lubricant fluids have molecular weights rangingfrom about 300 to about 600 and freezing and pour points from .about -40to less than about F. Their flash and fire points range from about 300F. to about 500 F. and their spontaneous ignition temperatures rangefrom about 100 to about 800 F. The diesters made by reacting adicarboxylic acid with a branched chain alcohol have been found to havesuperior viscometric properties as compared with diesters made byreacting dihydric alcohols with mono-carboxylic acids and thus, diestersprepared by the former method are preferred in formulating the lubricantcompositions of this invention.

The diester oils may be formed by the reaction of a polycarboxylic acidwith a mono-hydric alcohol, the reaction of a polyhydric alcohol with amono-carboxylic acid, reaction between a polyhydric alcohol with apolycarboxylic acid, or combinations of the above react-ions; forexample, reaction of a polycarboxylic acid with a glycol and amono-hydric alcohol, reaction of a glycol with a polycarboxylic acid anda mono-carboxylic acid, or the reaction of a glycol, a mono hydricalcohol, a polycarboxylic acid and a mono-carboxylic acid. The acids maybe mono-carboxylic aliphatic acids such as propionic acid, valeric acid,2-eflhyl enanthic acid, 2,2-dipropyl butyric acid or 3-(2-methylhexyl)valeric acid. They may contain unsaturated linkages as in senecioicacid, sorbic acid, or angelic acid; they may be polycarboxylic aliphaticacids such as succinic acid, glutaric acid, azelaic acid,S-octene-1,8-dicarboxylic acid, or 3-hexane 2,3,4- tricarboxylic acid,and they may be aromatic or cycloalip'hatic acids, such as cyclohexaneacetic acid, l,4-cyclopentylenebis acetic acid, phthalic acid,hemimellitic acid, and terephthalic acid.

The alcohols used in preparing the polyester lubricant base materialsmay be aliphatic mono-hydric alcohols such as propanol,2-ethyl-3-hexan0l, 2-ethyl-4-propyl heptanol, 2-butenol, or 2-methylpropanol. They may be polyhydric aliphatic alcohols, such as1,6-hexamethylene glycol, 1,10-decamethylene glycol, 2-hexene-1,6-diol,and 1,6-heptylene glycol; and they may be mono or polyhydric alicyclicor aromatic alcohols, such as 4-[m-(2- hydroxyethyl)phenyl] butanol,3-(2-hydroxyethyl) cyclohexanebutanol, p-(hydroxymethyl) phenethylalcohol, u-methyl-p-xylene-a,oU-diol,1,4-cyclohexane-a,tad-diethyldimethanol, 2,3 bis (4 hydroxybutyl) benzylalcohol 4,4[3-( 3 hydroxyhexyl) o phenylene1dibutanol, and S [3 (3hydroxypropyl)cyclopenta 2,4 dienylene1- 3cthyl amyl alcohol.

Thus the compounds of this invention very effectively enhance theoxidation resistance of such diester oils as diethyl oxalate;di-sec-butyl malonate; di-(2-hexyl) succinate; di-(isoheptyl) pimelate;di-(3-decyl) suberate;

di-sec-amyl glutarate; di-(isobutyl) g-lutarate; di-(2-ethylbutyl)glutarate; di-(2-ethylhexyl) glutarate; di-sec-amyl adipate;di-(3-methylbutyl adipate; diethyl adipate; di-2- ethyl'hexyl adipate;di-sec-amyl azelate; di-(isobutyl) azelate; di-(Z-ethylhexyl) azelate;di-sec-amyl sebacate; d-i-sec-butyl sebacate; di-(Z-ethylhexyl)sebacate; the glutarates, adipates, azelates and sebacates of branchedchain secondary alcohols, such as undecanol, tetradecanol, etc., and ingeneral diesters of the type described in the literature and above asuseful for synthetic lubricant purposes.

Another class of synthetic lubricants which achieve enhanced oxidativestability by the practice of this invention includes the siliconelubricants. The term silicone as used herein is defined as a syntheticcompound containing silicon and organic groups. In naming specificcompounds, the nomenclature system recommended by the American ChemicalSociety Committee on Nomenclature, Spelling, and Pronunciation (Chem.Eng. News, 24, 1233 (1946) will be used. Thus, the compounds which havethe SiO-Si-linkages are the siloxanes. Derivatives of silane, SiH inwhich one or more of the hydrogens in silane are replaced with organicgroups are termed the silanes. Silicates and silicate ester compoundsare named as oxy derivatives of silane and are called alkoxy or aryloxysilanes.

The silicone oils and greases serving as the base medium for thelubricant compositions of the invention include the polysiloxane oilsand greases of the type, polyalkyl-, polyaryl-, polyalkoxy-, andpolyaryloxy-, such as polydimethyl siloxane, polymethylphenyl siloxane,and polymethoxyphenoxy siloxane. Further included are silicate esteroils, such as tetraalkyloxy and tetraaryloxy silanes of thetetra-2-ethylhexy1 and tetra-p-tert-butylphenyl types, and the silanes.Also included are the halogensubstituted siloxanes such as thechlorophenylpolysiloxanes.

The polyalkyl, polyaryl, and polyalkyl polyaryl siloxanes are thepreferred types of base medium for the silicon containing lubricantcompositions of the invention because of their high oxidative stabilityover a wide temperature range. The polya-lkyl siloxanes, such as thedimethyl polysiloxane, are slightly preferred over the polyaryl andpolyalkyl polyaryl siloxanes because they show the least change inviscosity over a Wide temperature range.

Certain halogen containing organic compounds have physical propertieswhich render them particularly well suited as lubricants. Ordinarily,the halogen is either chlorine or fluorine. Typical of the chlorinatedorganic compounds suitable as lubricants are the chlorodiphenyls,chloronaphthalene, chlorodiphenyl oxides and chloronated paraflin waxes.

The fluorocarbon lubricants which are enhanced by this invention arelinear polymers built up of a recurring unit which is The fluorocarbonoils and greases are very stable chemically and have high thermalstability. These desirable physical properties appear to be closelyrelated to the bond distances occurring in the fluorocarbon polymericmolecule, which may also contain chlorine bonded to carbon.

Polyalkylene glycol lubricants which are benefited by the practice ofthis invention are ordinarily the reaction product of an aliphaticalcohol with an alkylene oxide. The preferred alkylene oxides areethylene oxide and propylene oxide. Depending upon the alcohol employedand the molecular weight of the compound, the polyalkylene glycollubricants may be either water insoluble or water soluble. The molecularweights of these polymers may vary from about 400 to over 3,000. Ingeneral, the polyalkylene glycol lubricants are characterized by highviscosity indices, low API gravities, low pour points and they have thegeneral formula:

where n is small integer and depends upon the alkylene oxide employedand x is a large integer from about 10 to about depending upon themolecular weight of the finished lubricant and R represents thehydrocarbon group derived from the particular aliphatic alcoholemployed.

Another important class of synthetic materials which are enhanced by thepractice of this invention are phos phate esters which are, in general,prepared by the reaction of an organic alcohol with phosphoric acid andhave the general formula:

where R, R and R" represent either hydrogen or an organic radical andwhere at least one of the groups represented by R, R and R" is anorganic radical. Typical of these materials is tricresylphosphate. Thephosphate esters are in general characterized by excellent fireresistant properties and high lubricity. However, their thermalstability is such that they are ordinarily unsuited for high temperatureapplications above about 300 F. Other examples of phosphate estersinclude: Tris-(2-chloro-l-methylethyl) phosphate; tri-n-butylphosphate;tris-(2-ethylhexyl)phosphate; triphenyl phosphate; tris(p-chlorophenyl)phosphate; diethyl m tolyl phosphate; .p-chlorophenyl dimethylphosphate; tris-(Z- n-butoxyethyl) phosphate; dimethyl m-tolylphosphate; din-propyl-m-tolyl phosphate; di-n-butyl phenyl phosphate;1,3-butylene ,B-chloroisopropyl phosphate; methyl di-m-tolyl phosphate;bis-(2-chloro-1-methylethyl) mtolyl phosphate; dimethyl 3,5-xylylphosphate; 4-chlorom-tolyl dimethyl phosphate;Z-ethyl-l-n-propyltrimethylene methyl phosphate; 4-chloro-m-tolyll-methyltrimethylene phosphate; dimethyl n-octyl phosphate, and thelike.

The mineral lubricating oils which are greatly benefited by the practiceof this invention are those derived from naturally occurring petroleumcrude by distillation and various other refining processes well known inthe art. These oils include lubricating and industrial oils such ascrankcase lubricating oils, transformer oils, turbine oils, transmissionfluids, cutting oils, gear oils, industrial oils, mineral white oils,glass annealing oils, oils thickened with soaps and inorganic thickeningagents (greases) and in general, engine and industrial oils which arederived from crude petroleum and are normally susceptible todeterioration in the presence of air, particularly at elevatedtemperatures and most particularly in the presence of metal containingcatalysts such as iron, iron oxide, copper and silver.

The greases used in formulating lubricant compositions of the inventionare formed by admixing a soap with an oil of any of the types describedabove. Such soaps are derived from animal or vegetable fats or fattyacids, wool grease, rosin, or petroleum acids. Typical examples are leadoleate, lithium stearate, aluminum tristearate, calcium glycerides,sodium oleate and the like. In addition, the polyester greases maycontain unreacted fat, fatty acids and alkali; unsaponifiable matterincluding glycerol and fatty alcohols; rosin or wool grease; water; andcertain additives which may function as modifiers or peptizers.

In formulating the grease compositions of this invention, greasesprepared by admixing a lithium soap with the polyester oils arepreferred as they have superior oxidative stability as compared withgreases formulated with other soaps, such as the sodium, calcium or leadsoaps.

In preparing the improved lubricant compositions of this invention, anappropriate quantity of 2,2-methyl- 7enebis-(4-halo-6-tert=butylp.henol) is blended with the lubricant to bestabilized. If desired, preformed concentrated solutions of thestabilizer in the base lubricant can be prepared and then subsequentlydiluted with additional lubricant to the desired concentration. Anadvantage of this invention is the fact that2,2'-rnethylenebis(4-halo-6tert-butylphenol) is easily and rapidlyblended with the base oil and because of the relative low melting pointof the stabilizer, there is no danger of separation of the stabilizerfrom the lubricant under normal use conditions. An additional advantageof this invention is that 2,2'-methylenebis-(4-halo-6tertabutylphenol)is highly compatible with the usual additives that are frequently usedto fortify lubricant compositions such as dete'rgent-dispersants,viscosity index improvers, dyes, anti-rust additives, anti-foamingagents, and the like.

The following examples illustrate various specific embodiments of thisinvention. The physical characteristics of the illustrative hydrocarbonoils used in the examples are shown in Table I TABLE I.PROPERTIES OFREPRESENTATIVE PETROLEUM HYDROCARBON OILS Oil I A B C D E F Gravity at60 API 30. 3 30. 5 28. 8 31. 1 20. 5 31. Viscosity, Saybolt:

Seconds at 100 F..." 178. 8 373. 8 309. 8 169.0 249. 4 335.4

Seconds at 210 F 52. 0 58. 4 63.8 51. 45. 7 68. 4 Viscosity Index 154.2107.4 141.9 157.8 35 8 144.4 Pour Point 30 20 0 Flash Point 410 465 365385 Sulfur, Percent 0.2 0.3 0. 3 0. 3 0. 3 0. 1

Example 1 To 100,000 parts of Oil A is added with stirring 12 parts(0.012 percent) of 2,2-methylenebis(4-chloro-6- tert-butylphenol). Theresulting oil is found to possess improved resistance to oxidativedeterioration.

Example 2 To 100,000 parts of Oil B is added 2,000 parts (2 percent) of2,2'-methylenebis-(4-bromo-6tert-butylphenol). On agitating thismixture, a homogeneous solution results and the resulting oilcomposition possesses enhanced oxidation resistance.

Example 3 With 100,000 parts of Oil C is blended 50 parts (0.50 percent)of 2,2'-methy1enebis-(4-iodo-6-tert-butylphenol) The resulting oilpossesses enhanced resistance against oxidative deterioration.

Example 4 To 100,000 parts of Oil D is added 100 parts (0.1 percent) of2,2'-rnethylenebis(4-br0mo-6-tert-butylphenol). The resulting oil isfound to possess enhanced resistance against oxidative deterioration.

Example 5 With 100,000 par-ts of Oil E is blended 5 parts (0.005percent) of 2,2 rnethylenebis (4-chloro-6-tert-butylphenol). Aftermixing the resulting oil possesses enhanced resistance to oxidation.

Example 6 To 100,000 parts of Oil F is added 150 parts (0.15 percent) of2,2'-methylenebis-(4-bromo-6-tert-butylph-enol). The resulting oilpossesses enhanced resistance against oxidative deterioration.

Example 7 With 100,000 parts of di-(sec-amyl) sebacate having aviscosity at 210 F. of 33.8 Saybolt Universal seconds (SUS), a viscosityindex of 133 and a molecular Weight of 342.5 is blended 100 parts (0.1percent) of 2,2'-methylenebis- (4 chloro 6-tert-butylphenol. Theresulting diester lubricant possesses greatly enhanced resistanceagainst oxidative deterioration.

Example 8 To 100,000 parts of di-(2-ethylhexyl) sebacate having aviscosity at 210 F. of 37.3 SUS, a viscosity index of 152 and amolecular Weight of 426.7 is added 1 part (0.001 percent) of2,2-methylenebis(4-iodo-6-tert-butylphenol). After mixing, the resultantdiester lubricant possesses greatly enhanced oxidation resistance.

Example 9 To 100,000 parts of di-(Z-ethylhexyl) adipate having aviscosity at 210 F. of 34.2 SUS, a viscosity index of 121 and amolecular weight of 370.6 is added 5,000 parts (5 percent) of2,2-rnethylenebis-(4-chloro-6-tert-butylphenol). After mixing, theresultant diester lubricant possesses outstanding resistance againstoxidiative deterioration.

Example 10 Three parts of2,2'-methylenebis-(4-chloro-6-tert-butylphenol) are blended and mixedwith 197 parts of a grease comprising 12.5 percent of lithium stear-ate,1 part of polybutene (12,000 molecular Weight), 2 percent of calciumxylyl stea-rate and 84.5 percent of di-(2-ethylhexyl) sebacate, toprepare an improved grease of this invention.

Example 12 One part of 2,2-methylenebis-(4-hromo-6-tert-butylphenol) isblended with 75 parts of diisooctyl adipate having a viscosity of 35.4S'US at 210 F., a viscosity of 57.3 SUS at 100 F., a viscosity of 3,980SUS at 40 F. and a viscosity of 22,500 at 65" F. Its viscosity index is143, its ASTM pour point is below F. and its specific gravity (60 F/60F.) is 0.926.

Example 13 An improved stable grease of this invention is prepared byblending 8 parts of 2,2-methylenebis-(4-chloro-6-tertbutylphenol) with 920 parts of grease comprising 12 percent of lithium stearate, 1 percentof poly-butene (12,000 molecular weight), 2 percent of calcium xylylstearate, 34.0 percent of di-(Z-ethylhexyl) sebacate and 51 percent ofdi-(2-ethylhexyl) adipate.

Example 14 Ten parts of 2,2'-methylenebis-(4-chloro-6-tert-butylphenol)are mixed with 10,000 parts of a grease comprising 11 percent of lithiumstearate, 1 percent of polybutene (12,000 molecular Weight), 1 percentof sorbitan monooleate, 86.6 percent ofdi-[I-(Z-methylpropyl)4-ethyloctyl] sebacate.

Example 15 Two parts of 2,2-methylenebis-(4-iodo-6-tert-butylphenol) areblended With parts of a polymethylpolyphenyl siloxane grease of mediumWeight consistency having a penetration of 240-280 (ASTM-217 18), aminimum melting point of 400 F. and a serviceable temperature range offrom 30 to 400 F.

Example 16 To a siloxane fluid having a viscosity of 71 centistokes at25 C. and 24 centistokes at 75 C., a specific gravity of 1.03 at 25 C.,a freezing point of 70 C. and a flash point of 540 F., which is composedof a halogen sub- 9 stituted polyphenylpolymethyl siloxane is addedsufficient 2,2'-methylenebis-(4-chloro-6-tert-butylphenol) to give acomposition containing 1.5 percent of the additive. This oil has anextremely high degree of resistance against oxidative deterioration dueto the presence of the 2,2- methylenebis- (4-chloro-6-tert-butylphenol)Example 17 To a phenylmethyl polysiloxane fluid having a viscosity of100-150 centistokes at 25 C., an open cup flash point of 575 F.(ASTM-D-92-33), a freezing point of 60 F., and a specific gravity of1.07 at 77 F. is added sufiicient 2,2-rnethylenebis(4-chloro-6-tertbuty1phenol) to give a composition containing 0.1 percent of theadditive.

Example 1 8 Ten parts of 2,2-methylenebis-(4-bromo-6-tert butylphenol)are blended with about 1,000 parts of monoethyl diethoxy monoacetoxysilane (boiling point 1915' C.) to prepare an enhanced oil of thisinvention.

Example 19 A one percent solution of 2,2-methylenebis-(4-chloro-6-tert-butylphenyl) in tribenzyl-n-hexadecyl silane (boiling point245248 C.) constitutes an improved lubricant within the scope of thisinvention.

Example 20 To a poly(trifluorochloroethylene) having the formula (CFCFCD and an average molecular weight of 880, pour point of C. and aviscosity of 45 centistokes at 160 F. is added 1.25 percent of2,2'-methylenebis-(4- iodo-6-tert-butylphenol) to prepare an improvedlubricant of this invention.

Example 21 A composition consisting of 0.01 percent of 2,2-niethylenebis-(4-ch1oro-6-tert-butylphenol) is prepared by blending anappropriate quantity of the compound with a fluorocarbon grease having apenetration of 267 millimeters at 77 F., 285 millimeters at 100 F. and300 millimeters at 125 F. (ASTM21748); and a dropping point of at least400 F. (ASTMD566-42).

Example 22 A composition containing 0.2 percent of 2,2-methy1-enebis-(4-bromo-6-tert-butylphenol) is prepared by adding an appropriatequantity of the compound to a polyalkylene glycol lubricant which isinsoluble in water and which has a Saybolt viscosity of 62.7 at 200 F.,a viscosity index of 146, ASTM pour point of 40 F., a fire point of 490F. and a specific gravity of 0.991.

Example 24 An improved lubricant of this invention comprising achlorinated organic compound is prepared by admixing 0.5 percent of2,2-rnethylenebis-(4-chloro-6-tert-butylphenol) with a chlorodiphenyloil having a distillation range of from 554 to 617 F., a Sayboltviscosity at 100 F. of about 49, a pour point of 30 F. and a specificgravity of about 1.267.

Example 25 An improved hydraulic fluid and lubricant according to thisinvention is prepared by adding 2 percent of 2,2- methylenebis-(4-chloro6 tert-butylphenol) to tricresyl phosphate.

10 Example 26 To illustrate the advantages achieved by the practice ofthis invention, particularly when the compositions are subjected toelevated temperature, runs were conducted using the Panel Coker Test.This test measures the oxidative stability of oils which are maintainedat elevated temperatures in the presence of air, the oils periodicallycoming in contact with a hot metal surface. This test is described inthe Aeronautical Standards of the Departments of Navy and Air Force,Spec. MILL 7808C, dated November 2, 1955. In these experiments, thediester lubricant was a commercially available di- (2-ethylhexyl)sebacate which was devoid of additives. The test was modified so thatthe Panel Coker apparatus was operated at 600 F. for 10 hours on acycling schcdulethe splasher being in operation for 5 seconds followedby a quiescent period of 55 seconds. On completion of these tests theextent by which the various test oils were decomposed under these hightemperature oxidizing conditions was determined by weighing the amountof deposits which formed on the metallic panel. Under these testconditions, the use of the additive free di-(2-ethylhexyl)sebacatecaused the formation of 138 milligrams of deposits on the metallicpanel. However, the presence of only 0.5 percent by weight of2,2-methylenebis-(4-chloro-6-tert-butylphenol) caused a substantialreduction in panel deposit.

Example 27 To further demonstrate the benefits resulting from thepractice of this invention, additional Panel Coker tests were carriedout using petroleum hydrocarbon lubricating oil. The test conditionswere identical with those above except that the temperature of thelubricants was maintained at 550 F. The base oil used was an initiallyadditive-free solvent-refined commercial neutral mineral lubricating oilhaving a viscosity at F. of 200 SUS and a viscosity index of 95. It wasfound that the additive free oil formed 434 milligrams of deposit on thepanel when subjected to the foregoing test conditions. However, when theoil had been treated with one percent by weight of2,2-methylenebis-(4-chloro-6-tertbutylphenol), there were only 82milligrams of deposit on the panel.

Example 28 To further illustrate the effectiveness of the 2,2-methylenebis-(4-halo-6-tert-butylphenol) compounds as lubricantadditives, tests were conducted on a highly refined mineral derived oilhaving a viscosity index of 106.5 and a viscosity of 87.1 SUS at 100 F.The oil was charged in separate samples (with and without an additive ofthis invention) to an apparatus for measuring the oxidative stability ofthe oil. The apparatus consists of a glass vessel having a 12 millilitercapacity and an inlet tube which can be connected to a mercurymanometer. After the oil is charged, the vessel is flushed with oxygenat atmospheric pressure and then connected to the mercury manometer. Thevessel is then immersed in a constant temperature bath at C. whereuponchanges in the oxygen pressure are indicated on the manometer. Themanometer is observed until a rapid pressure drop in the vessel occurs.The time from immersion to the initiation of the pressure drop is theinduction period of the oil. To all samples, ferric hexoate is added tocatalyze oxidation and make the test more severe. The concentration ofthe iron salt is adjusted to 0.05 percent based on Fe O One milliliterof the oil is charged to the apparatus in each test. In tests of thisnature the base oil has an induction period of from 2 to 3 minutes,showing that it is completely unstable to oxidative deterioration at 150C. However, when the oil contained 1.O l0 moles per liter of2,2'-methylenebis-(4-chloro-6-tert-butylphenol), the induction time was349 minutes. Thus the stability of the oil was raised 1 1 by theenormous factor of about 115-175 times its original value.

Example 29 Another illustration of the improvements in oil stabilityachieved by the practice of this invention are shown by PolyveriformOxidation Stability Tests, described in the paper entitled FactorsCausing Lubricating Oil Deterioration in Engines (Industrial andEngineering Chemistry, Analytical edition, 17, 302, (1945)). See also ABearing Corrosion Test for Lubricating Oils and Its Correlation withEngine Performance (Analytical Chemistry, 21, 737, (1949)). This testeffectively evaluates the performance of lubricating oil antioxidants.The test equipment and procedure employed and correlations of theresults with engine performance are discussed in the first paper abovementioned.

The amount of oxidation taking place during the test is measured interms of acid number and viscosity increase of the oil. By contrasting acomposition of this invention with a similar oil not containing anadditive of this invention, the outstanding benefits are illustrated.For example, in a set of tests conducted as described in the firstreference cited above, modified to the extent that the steel and coppertest piece described in the publication were omitted, a non-additivelubricating oil was compared with the same oil containing 1.0 weightpercent of the preferred compound of this invention, 2,2methylenebis-(4-chloro-6-tert-butylphenol). In order to make the test assevere as possible 70 liters of air per hour were passed through the oilfor a period of hours while the oil temperature was maintained at 300 F.The non-additive oil had an acid number of 6.0 after completion of thetest and its viscosity had increased by 103 percent. In distinction tothis the sample of oil containing 1.0 weight percent of2,2'-methylenebis-(4-chloro- 6-tert-butylphenol) had an acid number ofonly 1.6 and had suffered only a 23 percent increase in viscosity duringthe test. In addition to this, essentially no sludge had formed in theoil of this invention.-

Example 30 To still further illustrate the benefits derived from thisinvention tests were conducted on an electromotive diesel oil having aviscosity index of 54 and a viscosity of 919 Saybolt Universal secondsat 100 F. In this test the oil is heated at 325 F. with agitation for120 hours. Two metal catalysts are employed to promote degradation ofthe oil, namely, a silver plated wrist pin bushing specimen and a coppermetal catalyst specimen. Degradation of the oil is determined by acidnumber after the test and percent viscosity increase at 100 F. Inaddition the condition of the silver specimen indicates poor performancein the oil. One sample of the oil employed in this test contained acommercially available zinc dithiosulfate in amount equivalent to 0.02weight percent phosphorus. In this test the acid number of the oilincreased to 2.6 and there was a 47 percent increase in the viscosity.However, when an oil containing 4 percent of a barium sulfonate and 0.05percent by weight of 2,2'-methylenebis-(4-chloro-6-tert-butylphenol) wassubjected to the test, the final acid number was only 0.5 and theviscosity had increased only 31 percent. In addition the silver testspecimen came through the test essentially unchanged.

In the lubricant compositions of this invention effective use can bemade of other additives which are known to the art, such as otherinhibitors, detergent-dispersants, pour point depressants, viscosityindex improvers, anti-foam agents, rust inhibitors, oiliness or filmstrength agents, dyes and the like. Of the inhibitors which can beeffectively used in combination with the additives of this invention aresulfurized sperm oil, sulfurized terpenes, sulfurized parafiin waxolefins, aromatic sulfides,

alkyl phenol sulfides, lecithin, neutralized dithiophos- 7 phates,phosphorous pentasulfide-terpene reaction products, diphenylamine,phenylnaphthyl amine, fi-naphthol, pyrogallol, and the like. Typical ofthe detergent additives that can be used in the compositions of thisinvention are metallic soaps of high molecular weight acids, such asaluminum naphthenates, calcium phenyl stearates, calcium alkylsalicylates, alkaline earth metal petroleum sulfonates, alkaline earthmetal alkyl phenol sulfides (barium amyl phenol sulfide, calcium octylphenol disulfide, etc.), metal salts of wax-substituted phenolderivatives and the like. Of the viscosity index improvers' and pourpoint depressants, effective use can be made of polymers of the estersof methacrylic acids and higher fatty alcohols and the correspondingpolymers of esters of acrylic acid and higher fatty alcohols. These andother additives which can be employed in the compositions of thisinvention will now be well known to those skilled in the art.

The compounds of this invention are particularly effective antioxidantsfor use in steam turbine oils. This is demonstrated by making use of thestandard test procedure of the American Society for Testing Materialsbearing ASTM designation D943-54. According to this test procedure, 300ml. of a suitable test oil is placed in contact with 60 ml. of water andthe resulting oil-water system is maintained at a temperature of 95 C.while passing oxygen therethrough at a rate of three liters per hour.Oxidation is catalyzed by the use of iron and copper wire. Periodicallymeasurements are made of the acid number of the test oil and failure ofan antioxidant is indicated by an acid number in excess of 2.0. It isfound that when the various compositions of this invention are added insmall antioxidant quantities to steam turbine oils, substantialresistance against oxidative deterioration results.

The compounds of this invention are very effective antioxidants forgrease. The potency of the compounds of this invention in this respectis demonstrated by conducting the Norma Hoffman Grease OxidationStability Test, ASTM Test Procedure D-942-50. It is found that thepresence of minor proportions of the compounds of this invention inconventional greases greatly inhibits oxidative deterioration. By way ofexample an initially antioxidant-free lithium base grease is modified tothe extent that it contains 0.5 percent by weight of the product ofExample 13, and is subjected to the above oxidation stability test. Itis found that the presence of the composition produced by the process ofthis invention greatly retards oxygen absortp ion by the grease.

The stabilizers of this invention are also excellent additives totetraalkyllead antiknock compositions. The tetraalkyllead antiknockagents which are stabilized according to this invention are representedby such compounds as tetramethyllead, tetraethyllead, tetrapropyllead,dimethyldiethyllead, trimethylethyllead, and the like, or mixturesthereof. Such compounds containing from 4 to about 12 carbon atoms, oneatom of lead and a plurality of lead-to-carbon bonds, are capable ofincreasing the octane quality of gasoline when employed therein inantiknock quantities-0.5 to 6.5 grams of lead per gallon.Halogen-containing compounds such as triethyllead bromide may also bestabilized according to this invention.

The scavengers which are preferably, but not necessarily, present in theantik-nock compositions of this invention are organic halide compoundswhich react with the lead during combustion in the engine to formvolatile lead halide. The halogen of these scavengers has an atomicweight between 35 and that is, the active scavenging ingredient ischlorine and/or bromine. Such 'scavengers include carbon tetrachloride,propylene dibromide, 2-chloro-2,3-dibromobutane, 1,2,3-tribromopropane,hexachloropropylene, mixed bromoxylenes, 1,4- dibromobutane,1,4-diohloropentane, fi,/3'-di-bromodiisopropyl ether,fl,,6-dichlorodiethyl ether, trichlorobenzene, dibromotoluenes, and ingeneral those disclosed in US.

Patents 1,592,954; 1,668,022; 2,364,921; 2,479,900; 2,479,- 901;2,479,902; 2,479,903; and 2,496,983. In short, We prefer to employscavengers containing only elements selected from the group consistingof carbon, hydrogen, bromine, chlorine and oxygen. The amount ofscavenger used is from about 0.5 to about 2.0 theories, a theory beingdefined as the quantity required to react with the lead to form leadhalidei.e. 2 atoms of halogen per atom of lead. When we use mixtures ofbromine-containing and chlorine-containing scavengers, particularlybromo and chlorohydrocarbons, we can employ concentrations andproportions as described in US. Patent 2,- 398,281. Such concentrationsare sufficient to control the amount of deposits formed in the engine.

The tetraalkyllead antiknock compositions of this invention may containother ingredients such as dyes for identification purposes, metaldeactivators, diluents and the like.

Antiknock compositions containing tetra-alkyllead antiknock agents areemployed by adding them to gasoline to improve the antiknock qualitythereof. Such gasolines both before and after addition of the antiknockfluid are benefited by the practice of this invention. Thus gasolines towhich have been added a compound of this invention are found to be morestable upon prolonged periods of storage.

The following examples illustrated gasoline embodiments of thisinvention.

Example 31 To 10,000 parts of a grade 115/145 aviation gasolinecontaining 4.5 ml. of tetraethyllead per gallon which has an initialboiling point of 110 F. and a final boiling point of 330 F. and an APIgravity of 71.0 is added 0.5 percent of 2,2 methylene bis (4 chloro 6tertbntylphen-ol) Example 32 To a gasoline containing 26.6 percentaromatics, 20.8 percent olefins and 52.6 percent saturates and which hasan API gravity of 621 is added 0.1 percent of 2,2- mehylenebis-4-bromo-6-tert-butylphenol) Similarly, the compounds of this inventionmay be added with benefit to gasoline of whatever nature and howeverprocessed.

As noted above the compounds of this invention are also extremely usefulin inhibiting and stabilizing nonpetroleum fats and oils normallysubject to the deteriorating effect of oxidative rancidity. Inparticular, compounds of this invention are excellent stabilizers foranimal fats and oils, especially lard, against the effects of rancidity.The compounds of this invention may be used in concentrations from 0.001to about 0.1 weight percent in this embodiment of the invention. Inaddition, an acid synergist may be employed to promote the activity ofthe additives of this invention. These synergists which mutuallycooperate with the compounds of this invention, particularly 2,2methylenebis(4 chloro-6-tert butylphenol) to produce adisproportionately large increase in effectiveness in stabilizing fattymaterials including citric acid, phosphoric acid, ascorbic acid, ethylacid phosphate, glucuronolactone phytic acid, tartaric acid and aconiticacid.

In formulating the stabilized non-petroleum fats and oils of thisinvention, the additive or combination of additives is incorporated byappropriate means into the substrate to be stabilized. Thus, in the caseof animal, vegetable and fish oils, the additive or combination ofadditives is added in appropriate quantity and the resulting mixtureagitated to insure homogeneity. Where the substrate is a solid at roomtemperatures-e.g., fats, butter, etc.the mixing is preferably carriedout at temperatures above the melting point of the substrate. When acombination of additives is used, they can be mixed with the substrateas a preformed mixture or can be separately blended therewith in eitherorder. Generally speaking, it is desirable to first dissolve theadditive or additive combination in high concentration in a smallportion of the material to be stabilized. The resulting concentratedsolution is then blended with the remaining bulk. Another way offacilitating the formulation of the composition of this invention is topre-dissolve the additive or combination of additives in a suitablesolvent, such as ethanol, glycerol, propylene glycol, etc. and then mixthe resultant solution with the material to be stabilized. However, thepreferred way of formulating the compositions of this invention is topro-dissolve the additive or additive mixture in a fatty acid partialester of a polyhydroxy compound, notably a monoglyceride, and then blendthis mixture with the material to be stabilized. The nature of thesemonoglyceride compositions is well known in the art and may be made fromeither animal or vegetable fats, with or without previous hydrogenation.These compositions generally contain about 40 percent of themonostearyl, monoolearyl, and/ or monopalrnityl glycerides or mixturesthereof with the balance comprising a mixture of diand tri-glycerides.Molecularly distilled monoglycerides may also be used for this purpose.These compositions will be apparent from the following examples.

Example 33 With 1,000 parts of melted lard is mixed 1 part (0.1 percent)of 2,2' methylenebis (4 chloro 6 tert butylphenol). After cooling thelard can be stored for long periods of time with-out the development ofrancidity.

Example 34 With 5,000 parts of cottonseed shortening is blended 0.05part (0.001 percent) of 2,2-methylenebis-(4-bromo- 6-tert-butylphenol).The resulting shortening has improved resistance against oxidativerancidity.

Example 35 In 2.5 parts of propylene glycol is dissolved with stirring 1part of 2,2-methylenebis-(4-iodo-6tert-butylphenol). The resultingvmixture is then added with stirring to 10,000 parts of cod liver oil.The resultant oil containing 0.01 percent of the additive possessesincreased resistance against oxidative deterioration.

Example 36 To 10,000 parts of corn oil are added with stirring 5 parts(0.05 percent) of 2,2'-methylenebis-(4-chloro-6- tert-butylp'henol) and2 parts (0.02 percent) of ascorbic acid. ity characteristics.

Example 37 To parts of monoglyceride (prepared from a partiallyhydrogenated vegetable oil) heated to F. is added with stirring 5 partsof 2,2-methylenebis-(4-bromo- 6-tert-butylphenol) and 4 parts of citricacid. Ten parts of the resultant monoglyceride formulation are addedwith stirring to 10,000 parts of melted prime steam lard. The lardcomposition so formed which contains 0.005 percent of2,2-methylenebis-(4-chloro-6-tert-butylphenol) and 0.004 percent ofcitric acid can be stored at room temperature for long periods of timewithout developing rancidity.

Hydrocarbon polymers which are stabilized against oxidativedeterioration according to this invention include natural rubber, GR-Sand GR-N rubbers, butyl rubber, methyl rubber, polybutene rubber,butadiene rubbers, piperylene rubbers, dimethylbiutadiene rubbers,polystyrene, polybutadiene, polyisobutylene, polyethylene,isobutylenestyrene copolymer and, in general, elastomeric hydrocarbonpolymers which are normally susceptible to oxidative deterioration. Suchpolymers are well known in the art and besides being susceptible ofoxidative deterioration are characterized by having molecular weightsabove about 10,000. The problem resulting from heat, light and Theresulting corn oil has improved storage stabil- Example 38 To asynthetic rubber master batch comprising 100 parts of GR-S rubber havingan average molecular weight of 60,000, parts of mixed zincpropionate-stearate, 50 parts of carbon black, 5 parts of road tar, 2parts of sulfur and 1.5 parts of mercaptobenzothiazole is incorporated1.5 parts of 2,2'-methylenebis-(4-chloro-6-tertbutylphenol). This batchi then cured for 60 minutes at 45 pounds per square inch of steampressure.

Example 39 One percent of 2,2'-methylenebis-(4-chloro-6-tertbutylphenol)is :added to a synthetic rubber master batch comprising 100 parts ofGR-S rubber having an average molecular weight of 100,000, 5 parts ofzinc stearate, 50 parts of carbon black, 5 parts of road tar, 2 parts ofsulfur and 1.5 parts of mercaptobenzothiazole. This batch is then curedas described in Example 38.

Example 40 Two parts of 2,2'-methylene-bis-(4-bromo-6-tert-butylphenol)is incorporated in 100 parts of raw butyl rubber prepared by thecopolymerization of 90 percent of isobutylene and percent of isopreneand having an average molecular wei-ght of 100,000.

Example 41 To 200 parts of raw --butyl rubber having an averagemolecular weight of 600,000 and prepared by copolylmerizing 95 percentof isobutylene and 5 percent of butadiene is added 1.5 parts of2,2-methylenebis-(4-chloro-6- tert-butylphenol) Example 42 To a masterbatch of GRN synthetic rubber comprising 100 parts of GR-N rubber havingan average molecular weight of 75,000, 5 parts of zinc stearate, 50parts of carbon black, 5 parts of road tar, 2 parts of sulfur and 2parts of mercaptobenzothiazole is added 5 percent based on the weight ofthe batch of 2,2'-methylenebis-(4-chloro- 6-tert-butylphenol) Example 43A dry blend of polystyrene and 2,2'-methylenebis-(4-chloro-6-tert-butylphenol) is prepared by mixing 1 part of this phenolwith 100 parts of polystyrene having an average molecular weight of50,000.

Example 44 0.25 percent by weight of 2,2'-m-ethylenebis-(4-chloro-6-tert-butylphenol) is incorporated in polybutadiene having an averagemolecular weight of 50,000.

Example 45 To natural rubber (Hevea) is added 0.02 percent of2,2'-methylenebis- (4-iodo-6-tert-butylphenol The above examplesillustrate the improved compositions of this invention. Other suchcompositions and the methods of preparing the same will now be apparentto the person skilled in the art. 1

Example 46 v To illustratethe enhanced oxygen resistance of thehydrocarbon polymer. compositions of this invention, a nat- 16 uralrubber compounded into a typical tire-tread formula is selected fortest. One requisite of such stocks is that the desirable propertiesincorporated therein by careful selection of the compounding ingredientsand cure time shall be maintained during extended periods of storage anduse in the presence of oxygen. Comparison of various rubber stocks isbest carried out on stocks initially having the same state of cure. Themost reliable means for determining the state of cure is by the T50test, ASTM designation: D59940T, described in the ASTM Standards for1952, Part 6. This test measures the temperature at which a test piecerecovers its elasticity when it is stretched at room temperature, frozenat a sufiiciently low temperature to cause it to lose its elasticproperties, and then gradually warmed. In practice the temperature notedis that at which the sample recovers to 50 percent of the originalelongation and is, therefore, referred to as the T-50 value. Stocks fortesting and comparison are cured for a time sufficient to have a T-50value of -4.5 C. so that a valid comparison of the properties can bemade. The accelerated aging is conducted by the procedure of ASTMdesignation: D-572-52, described in the ASTM Standards for 1952, Part 6,for a period of 96 hours at a temperature of 70 C., with an initialoxygen pressure in the test bomb of 300 pounds per square inch gauge onspecimens having the following composition:

Parts by weight Smoked sheets 100.00

Carbon black 45.00

Zinc oxide 5.00

Stearic acid 3.00

Pine tar oil 2.00

Sulfur 3.00 Mercaptobenzothiazole 0.65

To demonstrate the protection afforded to the rubber by the inhibitorsof this invention, the tensile strength and the ultimate elongation ofstocks prepared by the addition of an inhibitor of our invention aredetermined before and after aging. These properties are compared withthe same properties determined on an identical rubber stock notprotected by an inhibitor. Both of these properties are determined bymeans of the test procedure of ASTM designation: D 41251T, fullydescribed in ASTM Standards for 1952, Part 6. The tensile strength isthe tension load per unit cross-sectional area required to break a testspecimen, while the ultimate elongation is the elongation at the momentof rupture of a test specimen. A decrease in the values for either ofthese properties upon aging represents a decrease in the usefulness ofthe article fabricated therefrom, so that the degree to which theseproperties are retained is a direct measure of the utility of theprotective substance.

The novel 2,2'-methylenebis-(4-halo-6-tert-butylphenol) compounds ofthis invention are prepared by a process which comprises reacting a4-halo-6-alkylphenol having the formula:

(C M k Example 47 In a reaction vessel equipped with reflux condenser,heating means, means for agitating reactants and means for chargingliquid reactants was placed 3142 parts of isopropanol and 66 parts ofpotassium hydroxide. The mixture was agitated until the potassiumhydroxide was completely dissolved at which point 1846 parts of 4-chloro-6-tert-butylphenol was added and the mixture was heated to 45 C.While maintaining the temperature, 420 parts of a 36.3 percent formalinsolution was added incrementally. The reaction temperature wasthereafter maintained with agitation for 6 hours, cooled to roomtemperature and acidified with about 200 parts of dilute hydrochloricacid. The acidified mixture was added to about 5500 parts of petroleumether, the isoproanol was extracted with water and the water phasediscarded. The organic phase was then distilled through a helix packedcolumn and 665 parts of 2,2'-methylenebis-(4- chloro-6-tert-butylphenol)were recovered at 209-213 C. at 0.3 ml. pressure. A portion of thismaterial was recrystallized from petroleum ether to yield white crystalsof pure 2,2'-methylenebis-(4-chloro-6-tert-butylphenol) having a meltingpoint of 114-114.5 C. Upon analysis these crystals were found to contain64 percent carbon, 6,6 percent hydrogen and 19.6 percent chlorine. Thecalculated content for the compound is 66.1 percent carbon, 6.8 percenthydrogen and 18.6 percent chlorine. An infrared spectrum of the compoundshowed bands of a partially hindered hydroxyl of a bisphenol compound.The ring substitution as determined from the infrared spectrum showedthe compound to contain a l,2,4,6-substituted benzene ring.

Example 48 Using isopropanol as a solvent 2-tert-butyl-4-chlorophenolwas reacted with 37 percent aqueous formaldehyde in the presence ofpotassium hydroxide as a catalyst for 17 hours at reflux temperature.The following procedure was used: 19 parts of the potassium hydroxidecontained in about 100 parts of isopropanol was added to the reactionvessel which was then flushed with nitrogen, 61 parts of2-tert-butyl-4-chlorophenol and about 7 parts of formaldehyde as a 37percent aqueous solution were simultaneously added. After the additionof the formaldehyde the reaction mixture was refluxed. After thereaction the mixture was taken up in n-hexane, washed well with water,dried and stripped under reduced pressure to remove the isopropanolsolvent. The product of this work-up procedure was a viscous oil whichwas fractionally distilled to yield '26 percent of the starting phenol,percent of 6-tert-butyl-4-chloro-2- hydroxymethylphenol (boiling point125127 C. at 0.5 mm. of mercury pressure) and 11 percent of 2,2'-methylenebis-(4 chloro 6 tert-butyl phenol), which boiled at 180220 C. at thereduced presure of 0.5 mm. and which had a melting point of 109-110" C.The structure of the compound was confirmed by infrared analysis.

Example 49 Following the procedure of Example 47, an appropriatequantity of 2-tert butyl-4-bromophenol is reacted with formaldehyde inthe presence of sodium hydroxide and ethanol to produce2,'2'-methylenebis-(4 brorno 6-tert- 'butylphenol).

Similarly, 2,2'-methylenebis- (4-iodo 6 tert-butylphenol) may beprepared by employing 2-tert-butyl-4-iodophenol as the startingmaterial.

In the above reaction a lower aliphatic alcohol is employed as asolvent. The preferred solvents are ethanol and isopropanol. Thereaction is conducted at temperatures varying from 20 to about 90 C. andmay be continued for from one-half to about 40 hours, depending upon thetemperature conditions employed.

The product 2,2'-methylenebis-(4-halo-6-tert-butylphenol) is preferablyrecovered from the reaction mixture by first stripping the solvent andthen distilling the reaction residue at reduced pressures. The reducedpressure employed should be adjusted so that the desired productdistills at temperatures in the range of from 100 to 250 18 C. andpreferably in the range of to about 220 C.

We claim:

1. Organic material normally tending to undergo oxidative deteriorationprotected against such deterioration by the inclusion therein of a smallantioxidant quantity, up to 5 percent, of a compound having the formula:

wherein X is a halogen selected from the class consisting of chlorine,bromine and iodine.

2. The composition of claim 1 wherein said compound is2,2-rnethylenebis(4-chloro-6-tert-butylphenol).

3. Petroleum-derived hydrocarbon compositions containing a smallstabilizing quantity, up to 5 percent, of a compound having the formula:

wherein X is a halogen selected from the class consisting of chlorine,bromine and iodine.

4. Hydrocarbon mineral lubricating oil containing as an antioxidanttherefor up to 5 percent of 2,2-methy-lenebis4-chloro-6-tert-butylphenol) 5. Gasoline containing as an antioxidant upto 5 percent of the compound2,2-methylenebis(4-chloro-6-tertbutylphenol) 6. A solid hydrocarbonpolymer normally susceptible to oxidative deterioration containing, inamount sufficient to inhibit such deterioration, a small antioxidantquantity of 2,'2-methylenebis(4-chloro-6-tert-butylphenol).

7. Sulfur vulcanized el-astomeric material selected from the classconsisting of natural and synthetic rubber, containing as an antioxidantfrom 0.001 to about 5 percent of a compound having the formula:

References Cited by the Examiner UNITED STATES PATENTS 2,542,972 2/1951Thompson 44-78 X 2,671,813 3/1954 Stofiel 260619 2,734,088 2/1956Knowles et al 25252 X 2,829,175 4/1958 Bowman et al 25252 X 2,999,8429/1961 Csendes 252404 X 3,012,049 12/1961 Bill 260-619 X DANIEL E.WYMAN, Primary Examiner.

I. E. DEMPSEY, Y. M. HARRIS, Assistant Examiners.

1. ORGANIC MATERIAL NORMALLY TENDING TO UNDERGO OXIDATIVE DETERIORATIONPROTECTED AGAINST SUCH DETERIORATION BY THE INCLUSION THEREIN OF A SMALLANTIOXIDANT QUANTITY, UP TO 5 PERCENT, OF A COMPOUND HAVING THE FORMULA:4. HYDROCARBON MINERAL LUBRICATING OIL CONTAINING AS AN ANTIOXIDANTTHEREFOR UP TO 5 PERCENT OF2,2''-METHYLENEBIS(4-CHLORO-6-TERT-BUTYLPHENOL).